Any references to methods, apparatus or documents of the prior art are not to be taken as constituting any evidence or admission that they formed, or form part of the common general knowledge.
Sheets of steel may be supplied in the form of coils or rolls. It will be appreciated that these coils are very heavy and typically require the use of a crane to move them. The approach to handling a coil is generally to pass a lower arm of a C-hook through the coil's lumen. The coil is then lifted by a hook attached to a mobile crane or the like. Other heavy loads of similar shape may be handled in like manner. For example, C-hooks may be used to handle concrete pipes and rolls of paper.
It will be realized that the centre or gravity of an unloaded C-hook differs from that of the hook in a loaded state. Consequently, a problem that occurs is that as the loaded C-hook is raised by the crane, the lower arm typically has a tendency to tilt downward toward the mouth of the hook, so that the load may slide off. Where a counterweight is used this tendency may be overcome however in that event the arm may tilt upward where a lighter than expected coil is loaded.
It is an object of the present invention to provide a lifting hook that addresses the above described problem and is an improvement, or at least a useful alternative, to lifting hooks of the prior art.